1. Field of the Invention
This invention relates to the field of security systems, and in particular to the field of distributed software controlled security systems.
2. Description of Related Art
Security systems are conventionally structured to protect an area. Sensors and other security devices are placed about an area to detect unauthorized access or trespass. Video cameras provide a view of the protected area; entry and exit portals report unauthorized openings or trespassing; motion sensor report unexpected movements; and so on. These systems are particularly well suited for protecting environments that have specific periods of expected inactivity. For example, a home security system is typically activated during the periods that the residents are absent or sleeping; the bulk of a business' security system is activated when the business is closed. The security of an area during periods of routine activity is particularly problematic. In most environments, the security of an area during periods of routine activity requires a conscious monitoring of the images from video cameras, personal patrolling of the area, and the like.
Some security systems, such as automobile alarms, are property specific, rather than area specific. These systems, however, typically operate as mobile area security systems. That is, an automobile alarm uses the same area protection scenario as a house alarm: unauthorized entry and unexpected motion during periods of expected inactivity. Some automobile security systems include an ability to report the automobile's location to a remote monitoring station, but in general automobile security systems are self contained and rely upon the activation of visual and audio attention-getting signals to encourage a potential thief to flee the scene.
In some situations, area security is the primary function of a security system, but in most cases, property security is the true function of an area security system. That is, for example, an area alarm system that detects motion in or around a swimming pool is intended to prevent harm to children or pets who may not appreciate the danger associated with the area. On the other hand, an area alarm system that detects motion in or about an office is intended to prevent theft of the items within the office. As noted above, the use of an area alarm system to protect property within the area has inherent limitations, particularly during periods of routine activity in that area.
Furthermore, the use of area security strategies for property security effects the same security measures, regardless of the status of the environment or the status of the individual property items. Entering an office to vacuum the floors is treated in the same manner as entering an office to steal a computer. If the area security system is armed, either entry will cause an alarm to be sounded; if the area security system is disarmed, neither entry will effect an alarm. Similarly, opening a car door while it is parked in a garage at home on a Saturday afternoon is treated in the same manner as opening the car door in the garage at 3 a.m. in the morning.